Final answer:
The Boston Port Act failed in its purpose because it united the colonies against British rule and led to the formation of the First Continental Congress.
Step-by-step explanation:
The Boston Port Act failed in its purpose because it had the unintended effect of uniting the colonies against British rule. The act, which closed the port of Boston until the town paid for the tea destroyed during the Boston Tea Party, was intended to isolate and punish Boston specifically. However, instead of quelling resistance, the act sparked outrage and support for Massachusetts from the other colonies. The closure of the port disrupted trade and caused economic hardship, prompting the colonies to mobilize and form the First Continental Congress in response to the Coercive Acts.